Welding machine



F. J. KRAUSE July 6, 1937.

WELDING MACHINE Filed. Feb. 4,

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.My 6, 193? J. KFQAUSE WELDING MACHINE Filed Feb. 4, 1936 '4 Sheets-Sheet 2 ATTORNEY WELDING MACHINE Filed Feb. 4-, 1936 4 Sheets Shee'h 3 0 min ENVENTOR ATTORNEY Juiy 6 1937. F, J. KRAUSE WELDING MACHINE Filed. Feb. 4. 1956 4 Sheets-Sheet 4 BNVENTOR fled J/ffawe 1 kg W 5 Q n ATTORNEY Patented July 6, 1937 PAENT OFFICE acsslsos "WELDING MACHINE Fred d. Krause, Chattanooga, Tenn, assignor to The Hedges-Walsh-Weidner Company; (Shah tanooga, Tenn.

Application February 4, 1936,, Serial No. $2,241

15 @laims.

This invention relates to arc welding and par ticularly to improvements in welding machines. A feature of the present invention is that weldlng may he carried on continuously without interruption for renewal of electrodes due to the provision of means for operating a pair of electrodes so as to feed them to the welding point in alternation. A second feature is that the occurrence of gaps or laps in the weld is avoided. A third feature resides in automatically oscillating an electrode transversely of the weld as it is advanced therealong.

Other features and advantages oi the inven tion will become apparent upon consideration of the following detailed description of an lllustra tive embodiment of the invention and the appended claims when read in conjunction with the accompanying drawings in which:

Figure l is a front elevation oi welding apparatus embodying the invention;

Figure 2 is a side elevation corresponding to Figure 1;

Figure 3 illustrates a detail oi the electrode operating mechanism;

Figures 4 and 5 are partly sectioned front and side elevatlonal views, respectively, showing the electrode holders on an enlarged scale;

Figure 6 is a partly sectioned plan view or" part of the oscillating mechanism for the welding head;

Figure 7 is an end view partly broken away, corresponding to Figure 6;

Figure 8 is a perspective view illustrating the construction of the travelling carriage that supports the, welding head;

Figure 9 is a side elevational view, partly sectioned and on an enlarged scale, of part oi the mechanism shown in Figure 8.

Referring first to Figures 1 and 2, the welding machine comprises a carriage it provided with traction wheels ll guided on a girder l2 and driven by a motor it through a suitable speed regulating device it to advance a pair of electrodes it, it mounted in a welding head it along the welding line A of the work B. The electrodes are supported in racks l8 slidably mounted in guides 20 on the welding head H, the guides being convergent at their lower ends so that the centre lines of the electrodes at their work ends are spaced about one-half inch, for example, along the welding line. A gear 2| engages the teeth of both racks l8 to continuously operate them in unison but in opposite directions so as to feed one electrode to the weld while retracting the un= consumed portion of the other. Gear it is ro-= tated first in one direction and then the other to feed and retract the electrodes in alternati Any suitable automatic reversing mechani may be employed for alternating the directio rotation of gear M, such as the well-known to illustrated in Fig. 3 comprising a slide 222 he g a rack 23 engaging a pinion it on the she of gear 26 and driven by a unidirectional s gear located between and alternately enga opposed'racks 2T], 28 on the slide. Gear at driven by a motor til through a variable s n regulating device 3!] and reduction gearing.

As illustrated in l and 5, the elect-re are slida oly mounted in their supporting 1 ill for movement relatively thereto tower away from the work. Each electrode is men in a holder having a shank 35 to which required electrical connections may he The shank extends through a bore in the i8 and a spring is mounted between the -e and nuts 3? which may be adjusted on the Si to regulate the position of the active en; or electrode with respect to the work. Levers ll attached to raclr and holder res tively, are connected in toggle fashion by a 412. When the handle portion lilo of lever depressed the electrode is moved downwardl atively to supporting racl; lil into contact the worlr to maize electrical contact there When handle is released spring he been compressed retracts the electrode and eetev lishes the arc.

During withdrawal of the unconsurned port oi an electrode its holder 3t may he raised respect to the upwardly moving rack it for viding an additional clearance of several in alcove the work to facilitate replacement at electrode. @n raising the lever handle we to tical position the holder is held in raised not due to the locking action of the toggle lever ll. When a fresh electrode has been and the holder 2343 has been raised so that pin is alcove a cam t3 mounted on a bracket pro ing from the welding head ill, the handle may he lowered until pin it strikes the cam. n dd acts to maintain the new electrode raised out of contact with the work and is shaped so that rack it continues its upward retracting move ment and pin 32 rides on the cam levers til, return toward normal position. Cam 43 is positioned to permit pin it to ride off the cam at lire time when upward movement of the rack ceases and its downward or feeding movement begins Holder 34 then drops to its normal position with respect to its rack l9 thus moving the new elec= trode downwardly to automatically take the are from the other as the direction of movement of the racks that support the electrodes is reversed.

As mentioned above, the centre lines of the active ends of electrodes l5, l6 are spaced along the welding line. Hence, unless special provision were made the rear electrode l5 would start welding at a point rearwardly of where the forward electrode l6 discontinued and conversely the latter would in turn continue from a point forwardly of where the rear electrode discontinued, thus producing laps or gaps in the weld. In order that this condition maybe obviated, or controlled as desired, the welding head i! is arranged to be automatically moved forwardly or backwardly with respect to the moving carriage I8 when either electrode takes up the weld from the other. As shown in Fig. 1, the welding head I! is provided with trunnions 44 journalled in exteriorly squared collars 45 slidably mounted on antifriction rollers 46 on brackets 4? extending from the plate 48 of carriage l8. Adjustably attached to the brackets 41 are members 58 providing supports for latches Si. is engageable with a cam 52 on the outer side of one of the electrode racks l8 and its other end face is engageable with the related member 5ft so that, on downward movement oi the related rack to feed. its electrode, the welding head I l is gradu ally moved in one direction or the other with re spect to the carriage, the extent of movement in each direction depending upon the slope of cams 52 and the adjustments of member 50. These movements result in compressing one of a pair of springs 53 mounted between nuts 5t and the brackets 4'5, the other being mounted on extensions of the trunnions 45. when the cam 52 of the active electrode rides on its latch 55, upon reversal of movement of the electrodes, the 001m pressed spring 53 acts to quickly shift the weld-- ing head ill on the carriage so that as the new electrode is brought into action it starts welding at the point at which the previously fed electrode discontinued, or at a determined point with re spect thereto. Thus, the occurrence of laps or gaps in the weld may be avoided, or controlled, as desired.

A link 55 (Figs. 2 and d to ill is connected by ball and socket joints at its ends to eccentric studs 56, 56a on shafts 51 and 58 mounted on carriage Hi and the welding head ll, respectively. By turning shaft 58 through a hand wheel 5! thereon the welding head may be pivoted. about its trunnions on brackets M to swing the electrodes l5, It in either direction across the welding line for adjusting them transversely thereof. Automatic oscillation of the electrodes transversely of the welding line during their movement longitudinally thereof may be effected by driving the shaft 51 through a sprocket and chain drive from the shaft 88 of reduction gearing associated with the electrode operating mechanism and driven by motor 30. Shaft 51 is mounted in clamp bearings 8| (Fig. 8) and normally held againstrotation so that eccentric stud 56 (Figs. 6 and 7) may oscillate the welding head by acting through link 65 against the carriage Ill. The amplitude of oscillation of the electrodes depends upon the eccentricity of stud 56 which may be regulated by providing any-suitable type of variable throw crank.

One end face of. each latch a screw 85 journalled at its ends in an annulus 86 attached to head 82. A planetary pinion 81 keyed to an extension of screw 65 meshes with bevel ring gears 88 and I8 rotatably mounted on annulus 86 and held in place by plates 1 I. Normally the entire assembly rotates with shaftil and the amplitude of oscillation of the electrodes corresponds with the existing eccentric adjustment of stud 56. By selectively engaging one of a pair of levers l2, Figs. 1 and 7, with nubs 13 on the ring gears 58, 10 either may be held against rotation thus driving pinion 61 to shift block 64 for varying the eccentricity of stud 58. With this arrangement the amplitude of oscillation of the welding head may be adjusted while the apparatus is in operation.

As shown in Figs. 8 and 9, the plate 48, carrying the brackets 41 that support the welding head I], is mounted for vertical movement in guides 14 on the base plate or frame I5 of carriage I8. A pair of shafts 16 extend through lugs TI on plate 48and lugs 18 on frame 15. The shafts 16 are threadedly engaged in sleeves 88 that may rest on the lugs I8 and which are interconnected by a bar 8! to prevent their rotation with the shafts. Byturning a hand wheel on a shaft 82 geared to shafts IS the plate 48, and hence the welding head ll, may be raised or lowered to adjust the electrodes vertically with respect to the work.

Collars 83 mounted on the sleeves are provided with pins 84 projecting through apertures in flanges 85 on the sleeves to engage the lugs 18 on carriage l6. Springs 86 are mounted between the collars 83 and nuts 81 on the sleeve 88. By screwing down the nuts 81 the sleeves 80 may be raised clear of the lugs 18 on carriage It) so that shafts 18 are raised and the plate 48 and welding head ll are resiliently supported on the carriage. A pivoted arm 88 connected to plate 48 carries a roller 88 riding in contact with the work. Arm 88 may be adjusted to vary the position of roller 98 by means of a rod 9i connected thereto and threaded in a fixed arm 92 extending from plate 48. on encountering vertical. irregularities or warped portions in the work, roller 88 acts to raise or lower plate 48 which carries the welding head and electrodes.

It should be noted that the automatic feeding and retraction of the electrodes in alternation cause a fresh electrode to be advanced to take the are from the other, when it has been consumed and starts to retract, so that the welding operation may be carried on without interruptions to replace electrodes.

The mounting of an electrode for movement in its supporting rack permits the electrode to be pushed down into contact with the work by manipulating lever handle 48a and upon release of the latter the electrode springs back automatically in just the right manner to strike an arc. This arrangement also obviates waiting until the rack and holder have receded far enough to provide clearance for inserting the new electrode. This is particularly advantageous because, otherwise, before such recession of the rack takes place there is not enough room to insert a new electrode and when it does take place the time remaining before reversal of the rack might be too short unless the operator acted promptly.

The resilient mounting of the electrode holder to its rack also precludes Jamming of the electrode against the work if it contacts the latter during welding since the electrode is yieldingly supported and may move upwardly several inches.

aosas oa The movements of an electrode relatively to its feeding rackthat may be efiected through lever its further afford a ready means for nursing the are by hand to overcome any disturbance and to re-establish normal welding conditions.

,Qam 43 acting to hold the new electrode in raised position until reversal of the rack and then automatically dropping it to working position at the right time relieves the operator of waiting for the electrodes to reverse and of the delicate operation of then attempting dropping the electrode to working position at the exact instant when the other electrode starts to retract and the new one begins to feed.

The automatic displacement of the welding head and electrodes relatively to the carriage through cams 52 and springs 53, by compensating for the necessary spacing of the ends of the electrodes to prevent interference, avoids the occurrence of gaps or laps in the weld.

it should also be noted that a proper gap between the end of the active electrode and the work is maintained despite irregularities in the latter because of the automatic vertical adjustment of the welding head on the carriage under the control of the contact roller St on lever Although a specific embodiment of the invention has been shown in the drawings and de-= scribed in detail herein, it is to be understood that many changes and variations might be made without departing from the invention and, therefore, it is desired and intended to include all such changes and variations within the scope of the appended claims.

What I claim is:

1. Welding apparatus comprising; a welding head; a pair of holders for consumable electrodes; individual supports for said holders mounted on said head for movement toward and away from the Welding point, said holders being displaceably mounted on said supports; means for con= tinuously moving said supports on said head alternately toward and away from the work to iced one electrode to the weld and to simultaneously retract the unconsumed portion of the other; and means for displacing the holder for said other, inactive, electrode in a direction away from the work to permit replacement of its electrode electrode with respect to its support for moving it further away from the weld to permit replacement of said electrode; and means controlling said other holder to hold the new electrode raised the welding point, said holders being displaceably mounted on said supports; means for moving said supports on said head in unison to alternately ieed one electrode to the weld and simultaneous- 1y retract the other; means for displacing the holder for said other electrode with respect to its support in a direction away from the weld to permit replacement of said electrode; and means operative to displace said other holder in the opposite direction on its support for positioning the new electrode in welding relation to the work substantially upon reversal of the movement of said holder supports.

Arc welding apparatus comprising; a welding head; a pair of holders for consumable elec trodes; individual supports for said holders mounted on said head for movement toward and away from the welding point, said holders being displaceably mounted on said supports; means for continuously moving said supports on said head alternately toward and'away from the work to feed one electrode to the weld and to simultaneously retract the unconsumed portion of the other; means for displacing the holder for said other electrode with respect to its support for moving it further away from the work to permit replacement of said electrode; and means cooperating with the holder for said other electrode to hold a new electrode therein raised out of welding position during the retracting movement of its holder and acting, upon reversal of movement thereof for feeding said electrode, to drop the new electrode into a position adjacent said one electrode to automatically take the are from the latter as it is retracted.

5. Arc welding apparatus comprising; a welding head; a holder for a consumable electrode; a support for said holder mounted on said head for movement toward and away from the welding point, said holder being displaceably mounted on said support; a lever connected to said holder and operable to advance the latter in its support for engaging its electrode with the worlz; and means operative on release of said lever for moving said holder and its electrode relatively to said support in a direction away from the work to strike the welding are.

6. Welding apparatus comprising; a Welding head; a pair of holders for consumable electrodes; individual supports for said holders mounted on said head for movement toward and away from the welding point, said holders being displaceably mounted on said supports; means for moving said supports on said head alternately toward and away from the work to feed one electrode to the weld and to simultaneously retract the unconsumed portion of the other; a lever connected to said holder for said other electrode and acting upon operation thereof to displace said holder relatively to its support and in a direction away from. the work; and means coopcrating with said lever to hold an electrode in said holder raised out of welding relation with the work.

7. Welding apparatus comprising; a welding head; a pair of holders for consumable elec- I trodes; individual support for said holders mounted on said head for movement toward and away from the welding point, said holders being displaceably mounted on said supports; means for moving said supports on said head alternately toward and away from the work to feed one electrode to the weld and to simultaneously retract the unconsumed portion of the other; a lever connected to said holder for said other electrode and operable to displace said holder relatively to its support and in a direction away from the work; and cam means on said head cooperating with said lever to maintain an electrode in said holder out of contact with the work during retracting movement of the support 'for said holder and acting to permit movement of said holder in said support toward the work, during retraction thereof, to position its electrode in welding relation to the work upon reversal of the movement of said support.

8. Welding apparatus comprising; a carriage movable along the welding line of the work; a welding head on said carriage; a pair of electrode holders movably mounted on said head and positioned so that the work ends of the related electrodes are spaced along the welding line; means for moving said holders to position the respective electrodes in welding relation to the work in alternation; and means for automatically displacing said electrode holders along the welding line to selectively position either of said electrodes for continuing welding from a determined point with respect to that at which the other electrode discontinued.

9. Welding apparatus comprising; a carriage movable along the welding line of the work; a welding head mounted on said carriage for displacement along the welding line with respect thereto; a pair of holders for consumable electrodes mounted on said head so that the work ends of the related electrodes are spaced from each other along the welding line; means for moving said holders on said head to position the respective electrodes in welding relation to the work in alternation; and means for displacingsaid head on said carriage to position either of said electrodes for continuing welding froma determined point with respect to that at which the other electrode discontinued.

10. Welding apparatus comprising: a carriage movable along the welding line of the work; a

welding head mounted on said carriage and displaceable along the welding line with respect thereto; a pair of holders for consumable electrodes mounted on said head so that the work ends of the related electrodes are spaced. from each other along the welding line; means for moving said holders on said head to position the respective electrodes in welding relation to the work in alternation; and means for displacing said head on said carriage and forwardly along the welding line to position the rearwardly disposed electrode at the point where the forwardly disposed electrode discontinued welding for avoiding lapping of the weld.

11. Welding apparatus comprising; a carriage movable along the welding line of the work; a welding head mounted on said carriage and displaceable along the welding line with respect thereto; a pair of holders for consumable electrodes mounted on said head so that the work ends of the related electrodes are spaced from each other along the welding line; means for moving said holders on said head to position the respective electrodes in welding relation to the work in alternation; and means for displacing said head on said carriage and rearwardly along the welding line to position the forwardly disposed electrode at the point where the rearwardly disposed electrode discontinued welding for avoiding a gap in the weld.

12. Welding apparatus comprising; a carriage movable along the welding line 01' the work; a welding head on said carriage; a pair of holders for consumable electrodes mounted on said head so that the work ends of the related electrodes displacing the holder for said other electrode along the welding line to position it for continuing welding at a determined point with respect to that at which said one electrode discontinued.

13. Welding apparatus comprising; a carriage movable along the welding line of the work; a welding head mounted on said carriage and displaceable along the welding line with respect thereto; a pair of holders for consumable electrodes mounted on said head so that the work ends of the related electrodes are spaced from each other along the welding line; means for moving said holders on said head to position the respective electrodes in welding relation to the work in alternation; and cam controlled means associated with said holders and said carriage acting to determinedly displace said welding head along the welding line with respect to said carriage.

14. Welding apparatus comprising; a carriage movable along the welding line of the work; a welding head mounted on said carriage and displaceable along the welding line with respect thereto; a pair of holders for consumable electrodes mounted on said head so that the work ends of the related electrodes are spaced from each other along the welding line; means for moving said holders on said head to position the respective electrodes in welding relation to the work in alternation; means controlled by the movements of said holders for displacing said welding head on said carriage to position either of said electrodes at a determined point with respect to that at which the other discontinues; and means associated with said holders for controlling said displacing means to regulate said movements of said welding head.

15. Are welding apparatus comprising; a welding head; a holder for a consumable electrode; a support for said holder mounted on said head for movement toward and awayirom the welding point, said holder being displaceably carried by said support; means for moving said support to feed said electrode to the work; a. lever connected to said holder and operable to advance the latter in its support for engaging its electrode with the work; and spring means mounted between said support and said holder so as to have energy stored therein upon said movement of said lever and acting, upon release of said lever, to move said holder and its electrode relatively to said support in a direction away from the work for striking the welding arc. Y

FRED J. KRAUSE. 

